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authorPaulo Alcantara <pc@cjr.nz>2021-05-03 11:55:26 -0300
committerSteve French <stfrench@microsoft.com>2021-05-04 11:52:56 -0500
commit5c1acf3fe05ce443edba5e2110c9e581765f66a8 (patch)
tree657dbc77464a9b56673aa149e13ba98a95be6b8c /fs/cifs
parent5b2abdafbedb902d7d8d3d5e571a38b8900dd15f (diff)
downloadlinux-5c1acf3fe05ce443edba5e2110c9e581765f66a8.tar.bz2
cifs: fix regression when mounting shares with prefix paths
The commit 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx") revealed an existing bug when mounting shares that contain a prefix path or DFS links. cifs_setup_volume_info() requires the @devname to contain the full path (UNC + prefix) to update the fs context with the new UNC and prepath values, however we were passing only the UNC path (old_ctx->UNC) in @device thus discarding any prefix paths. Instead of concatenating both old_ctx->{UNC,prepath} and pass it in @devname, just keep the dup'ed values of UNC and prepath in cifs_sb->ctx after calling smb3_fs_context_dup(), and fix smb3_parse_devname() to correctly parse and not leak the new UNC and prefix paths. Cc: <stable@vger.kernel.org> # v5.11+ Fixes: 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx") Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Acked-by: David Disseldorp <ddiss@suse.de> Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs')
-rw-r--r--fs/cifs/cifsfs.c8
-rw-r--r--fs/cifs/connect.c24
-rw-r--r--fs/cifs/fs_context.c4
3 files changed, 23 insertions, 13 deletions
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 8a6894577697..d7ea9c5fe0f8 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -863,13 +863,7 @@ cifs_smb3_do_mount(struct file_system_type *fs_type,
goto out;
}
- /* cifs_setup_volume_info->smb3_parse_devname() redups UNC & prepath */
- kfree(cifs_sb->ctx->UNC);
- cifs_sb->ctx->UNC = NULL;
- kfree(cifs_sb->ctx->prepath);
- cifs_sb->ctx->prepath = NULL;
-
- rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, old_ctx->UNC);
+ rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, NULL);
if (rc) {
root = ERR_PTR(rc);
goto out;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index d7efbcb2d5df..495c395f9def 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3149,17 +3149,29 @@ out:
int
cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
{
- int rc = 0;
+ int rc;
- smb3_parse_devname(devname, ctx);
+ if (devname) {
+ cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
+ rc = smb3_parse_devname(devname, ctx);
+ if (rc) {
+ cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
+ return rc;
+ }
+ }
if (mntopts) {
char *ip;
- cifs_dbg(FYI, "%s: mntopts=%s\n", __func__, mntopts);
rc = smb3_parse_opt(mntopts, "ip", &ip);
- if (!rc && !cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip,
- strlen(ip))) {
+ if (rc) {
+ cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
+ return rc;
+ }
+
+ rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
+ kfree(ip);
+ if (!rc) {
cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
return -EINVAL;
}
@@ -3179,7 +3191,7 @@ cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const c
return -EINVAL;
}
- return rc;
+ return 0;
}
static int
diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c
index 1d6e0e15b034..3bcf881c3ae9 100644
--- a/fs/cifs/fs_context.c
+++ b/fs/cifs/fs_context.c
@@ -476,6 +476,7 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx)
/* move "pos" up to delimiter or NULL */
pos += len;
+ kfree(ctx->UNC);
ctx->UNC = kstrndup(devname, pos - devname, GFP_KERNEL);
if (!ctx->UNC)
return -ENOMEM;
@@ -486,6 +487,9 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx)
if (*pos == '/' || *pos == '\\')
pos++;
+ kfree(ctx->prepath);
+ ctx->prepath = NULL;
+
/* If pos is NULL then no prepath */
if (!*pos)
return 0;